Comcast customers who sued the Philadelphia-based company back in 2003, alleging the Philadelphia cable company set up an illegal "monopoly" in Philadelphia and other markets when it bought the former Lenfest and AT&T cable operations, among others, have "demonstrated that this case can proceed as a class action," the U.S. Third Circuit Court of Appeals in Philadelphia ruled Wednesday. Case is USDC E.Pa. 03-6604, read the ruling here.

Comcast's challenges to whether its customers in major metro regions really form a valid class failed to convince the judges to throw out the complaint, which had been certified as a class action by the district court.

The customers' complaint also says Comcast wrongly "interfered with" efforts by RCN Telecom Services to enter the market as a competitor so it could charge higher prices than a free market would have allowed, by discouraging Comcast contractors from also serving RCN.

Comcast lawyer Michael S. Shuster of Kasowitz, Benson, Torres & Friedman did not immediately respond to a request for comment on the court's opinion, or whether Comcast would appeal.

The Comcast customers and their lawyers aren't asking for the company to be broken up. They want money: Lawyer Barry Barnett of Texas-based Susman Godfrey LLP, who represents the customers, told me experts for his clients estimated damages at $876 million just for Philadelphia-area Comcast customers in 2009, and similar complaints are pending for Comcast customers in Boston and Chicago. Any award eventually made by federal courts could be tripled, he added, under the federal Sherman Antitrust Act.